Targeted biopsies may trigger prostate cancer reclassification

(HealthDay News) — Targeted prostate biopsy using multi-parametric magnetic resonance imaging-ultrasound fusion (mpMRI-US) may lead to reclassification of prostate cancer that was initially diagnosed as low-risk, according to research published in The Journal of Urology.

Jim C. Hu, M.D., M.P.H., of the David Geffen School of Medicine at the University of California Los Angeles, and colleagues identified 113 men (median age, 64 years; prostate-specific antigen, 4.2 ng/mL; prostate volume, 46.8 cc) under active surveillance for low-risk prostate cancer. The patients subsequently received confirmatory, targeted biopsy using mpMRI-US.

The researchers found that confirmatory fusion biopsy led to reclassification of prostate cancer in 41 men (36 percent), including 26 men (23 percent) with Gleason grade greater than 6 and 15 men (13 percent) with high-volume Gleason grade 6 disease. According to stratification by suspicion on mpMRI, the probability of reclassification was 24 to 29 percent for target grade 0 to 3, 45 percent for target grade 4, and 100 percent for target grade 5 (P = 0.001). Men with prostate cancer that was grade 4 or 5, compared with lower target grades, were greater than three times more likely to have their disease reclassified (odds ratio, 3.2; 95 percent confidence interval, 1.4 to 7.1; P = 0.006).

“Upon confirmatory re-biopsy using mpMRI-US, men with high-suspicion mpMRI targets were frequently reclassified (45 to 100 percent),” the authors write.